MCDOWELL GROUP 2011 Sea Otter Impacts Report

Sea Otter Impacts on

Commercial Fisheries in Southeast Alaska

Prepared for: Southeast Alaska Regional Dive Fisheries Association

November 2011

Sea Otter Impacts on

Commercial Fisheries in Southeast Alaska

Prepared for: Southeast Alaska Regional Dive Fisheries Association

Prepared by:

Juneau • Anchorage

November 2011

Table of Contents

Executive Summary .................................................................................................................. 1

Introduction .............................................................................................................................. 7

Sea Otters in Southeast Alaska................................................................................................. 8

Southeast Alaska Dive Fisheries ............................................................................................. 12

Geoduck Clams ..................................................................................................................... 12 Sea Cucumbers ...................................................................................................................... 13 Red Sea Urchins ..................................................................................................................... 14

Economic Impacts of Sea Otter Predation ............................................................................. 15

Sea Cucumbers ...................................................................................................................... 16 Geoducks ............................................................................................................................... 18 Red Sea Urchins ..................................................................................................................... 20 Dungeness Crab ..................................................................................................................... 22

Quantifying the Impact of Sea Otter Predation .................................................................... 24

Sea Otter Predation Impacts on Communities ...................................................................... 26

Literature Referenced ............................................................................................................. 27

Appendix 1: Map of Otters in Southeast Alaska ................................................................... 29

Appendix 2: Impact of Sea Otters on Dive Fishery Areas .................................................... 30

Sea Cucumbers ...................................................................................................................... 30 Geoduck Clams ...................................................................................................................... 31 Red Sea Urchins ..................................................................................................................... 32

Sea Otter Impacts on Commercial Fisheries in Southeast Alaska McDowell Group, Inc. • Page 1

Executive Summary

Purpose

The purpose of this report is to estimate the economic loss to Southeast Alaska commercial fisheries due to

growing sea otter predation. The sea cucumber, geoduck, red sea urchin, and Dungeness crab fisheries are

examined. This current document is an update of a similar economic loss assessment conducted by McDowell

Group at the end of 2005. The 2005 study was, in turn, based on estimated loss of commercial species

volume and ex-vessel value calculated by the Alaska Department of Fish and Game (ADFG). This current study

uses similar methodology utilizing data collected by ADFG.

Methodology

Economic loss estimates in this report are based on scientific biomass data generated by subdistrict bottom

surveys conducted by ADFG biologists and divers. Every dive fishery area is surveyed by ADFG divers on a

rotational basis in transects prior to commercial openings in order to calculate biomass and generate

Guideline Harvest Limits (GHL) for each fishery. Staff (primarily biologists) then note fishery areas which

display physical evidence of sea otter predation and areas where sea otters are active.

McDowell Group has consulted extensively with ADFG staff and employed the same methods to calculate the

estimated loss due to sea otter predation in the sea cucumber, geoduck, and red sea urchin fishery. In the

Dungeness crab fishery, areas with high otter populations were compared to those with fewer otters to

estimate the volume lost due to sea otter predation. Methodology is described in detail in this report body.

Summary of Study Findings

Economic Impacts of Sea Otter Predation on Commercial Species

• Sea otter predation in the red sea cucumber, geoduck clam, red sea urchin, and Dungeness crab

fisheries is estimated to have cost the Southeast Alaska economy $28.3 million in direct, indirect, and

induced impacts since 1995.

Economic Impacts of Sea Otter Predation on Southeast Alaska Commercial Fisheries

Fishery Estimated Pounds

Lost due to Sea Otter Predation

Estimated Ex-Vessel Value Lost Due to

Sea Otter Predation

Estimated Wholesale Value Lost Due to Sea Otter Predation

Time Period

Sea Cucumbers 3,254,000 $5,294,000 $8,951,000 1996-2011

Geoducks 530,500 3,237,000 4,210,000 2005-2011

Red Sea Urchins 3,102,000 1,024,000 3,972,000 1995-2005

Dungeness Crab 2,681,000 3,317,000 5,301,000 2000-2010

Total 9,567,500 $12,872,000 $22,434,000 -

Source: ADFG data and McDowell Group estimates.


• Since 1995, it is estimated $22.4 million in wholesale value has been lost due to sea otter predation.

The secondary (multiplier) impact of these losses on the regional economy is estimated to be an

additional $5.8 million, for a total of $28.2 million.

• Dive fisheries and Dungeness crab fisheries in Southeast Alaska had a first wholesale value of $25

million in 2010, employing roughly 625 fishermen as well as processing workers and tender

operators. The secondary economic activity resulting from these fisheries is estimated to be $6.5

million or equivalent to 59 full-time jobs.

Sea Cucumbers

• Since 1995, the sea cucumber fishery has lost an estimated 3.3 million pounds worth $9.0 million in

wholesale terms, and $5.3 million in ex-vessel terms, due to sea otter predation.

• Sea otter impacts were particularly harmful in 2011, as an estimated 235,000 pounds was lost due to

predation worth $2.23 million in wholesale value.

• As a result of sea otter predation, the average commercial diver harvesting sea cucumbers in 2011

lost an estimated $7,000 in ex-vessel value.

• Since 1992, ADFG has closed seven areas either specifically due to sea otter predation or presumably

due to sea otter predation. Sea otters have been noted to be negatively affecting 12 other harvest

areas. See Appendix 2 for a complete list and map of fishery areas affected by sea otter predation.

Geoduck Clams

• Since 2005, the geoduck clam fishery has lost an estimated 530,500 pounds worth $4.2 million in

wholesale terms, and $3.2 million in ex-vessel terms, due to sea otter predation.

• Impacts were particularly costly in 2011, as an estimated 140,900 pounds were lost due to predation

worth $2.0 million in wholesale value.

• As a result of sea otter predation, the average commercial diver harvesting geoducks in 2011 lost an

estimated $20,000 in ex-vessel value.

• No geoduck harvest areas have yet been closed due to sea otter predation, but ADFG has identified

27 fishery areas with evidence of sea otter predation. About 70 percent of the commercial geoduck

harvest comes from these 27 fishery areas, where surveys note large craters and shell fragments left

over from sea otter predation.

• Although no areas have yet been closed due to sea otter predation, some prospective fishery areas

found by commercial divers with sizable geoduck populations were never proposed to ADFG and

therefore never opened. Sea otter predation in the area made it likely the fishery would not be worth

surveying and managing by the time it could be opened (Doherty 2011, personal communication).


Red Sea Urchin

• The harvest of red sea urchins has declined substantially since 2006. Industry sources indicate only

one or two divers are harvesting urchins in 2011, with only one active buyer. Sea otter predation

impacts since 2005 have not been compiled, due to the decline of the fishery and the confidential

nature of most data associated with it.

• The decline of the red sea urchin fishery in recent years is related to market factors and not due to sea

otter predation.

• Prior to 2006, an estimated 3.1 million pounds of sea urchin harvest was lost due to sea otter

predation, worth $4.0 million in wholesale value.

• Despite declining effort in the sea urchin fishery, sea otter predation continues to negatively impact

stocks. The 2011/12 red sea urchin GHL is 3.28 million pounds, a 40 percent decline from the

2008/09 GHL of 5.44 million pounds. If the market value rebounds and fishery participation

increases, the lost GHL due to sea otters will be realized in future years as GHL’s are expected to

decline.

Dungeness Crab

• Sea otters regularly eat Dungeness crab, which are an attractive food source given their abundance in

Southeast Alaska, considerable size, and relative ease of capture.

Comparison of Southeast Alaska Dungeness Crab Harvest

in Districts with Major Vs. Minor Sea Otter Presence

Note: Districts with major sea otter presence include districts: 3, 5, 6, 9, 10, and 13. Source: ADFG harvest data.

0

500,000

1,000,000

1,500,000

2,000,000

2,500,000

3,000,000

Avg. Harvest 2000-2002 Avg. Harvest 2008-2010

Har

vest

Vo

lum

e (l

bs.

)

Districts with Major Sea Otter Presence Districts with Little Sea Otter Presence


• The three-year average harvest from districts with significant sea otter presence was 975,000 pounds

less in 2008 through 2010, compared to the 2000-2002 period, a decline of 38 percent. In

comparison, districts with less sea otter presence saw average harvests increase 151,000 pounds

between the two periods, an increase of 7 percent.

• The Southeast Alaska Dungeness crab fishery has lost an estimated 2.7 million pounds of commercial

harvest due to sea otter predation since 2000, worth $3.3 million in ex-vessel terms and $5.3 million

in wholesale value.

Sea Otter Population Growth

According to available data, the Southeast Alaska sea otter population has increased significantly, particularly

in southern Southeast Alaska where the region’s dive fisheries occur. The most recent population survey was

completed in 2002 and 2003, indicating a Southeast Alaska population estimate of 8,949 animals. More

recent studies suggest annual growth rates are 12 percent in southern Southeast Alaska and 4 percent in

northern Southeast Alaska (Hoyt 2011, personal communication). Other authoritative literature suggests sea

otter populations can grow at an annual rate of 20 percent per year when expanding into new territory (Paul

2009).

The Southeast Alaska sea otter population is projected to be approximately 19,000 in 2011, increasing from

less than 9,000 animals in the most recent published population estimate. By 2015, the Southeast population

is expected to approach 28,000 animals. These estimates incorporate the subsistence harvest of sea otters by

Alaska Natives.

Estimated Southeast Alaska Sea Otter Population, 2002 - 2015

Season Last Population

Survey (2002/2003)

Projected 2011 Population


Survey Coefficient of

Variation (CV%)

Southern Southeast

12% Annual Growth Rate 5,8451 14,472 22,772 0.14 Northern Southeast (including Glacier Bay) 4% Annual Growth Rate 3,1042 4,418 5,168 0.16

Total Southeast Alaska

Estimated Population 8,949 18,890 27,940 - 1Population estimate is from 2003. 2Population estimate is from 2002. Source: U.S. Fish and Wildlife Service, Hoyt 2011 (personal communication), and McDowell Group calculations.

Given current foraging research, a conservative estimate about body weight (50 lbs.) and daily food intake

(20 percent of body weight); a sea otter population of 27,940 would consume just over 10 million pounds of

commercial species per year in Southeast Alaska. The entire 2010 Southeast Alaska harvest in the dive and

Dungeness crab fisheries was 5.9 million pounds.


Abalone

A commercial fishery for northern abalone (Haliotis kamtschatkana) existed in Southeast Alaska from the late

1970s to mid 1990s. Guideline harvest levels where not applied until the 1980/81 season and the fishery

slowing declined thereafter. Similar collapses occurred in British Columbia and Washington state.

The fishery collapsed almost certainly because of excessive harvests in the late 1970s and early 1980s. There

was not a sufficient stock assessment or research program in place when the Alaska fishery boomed and there

was insufficient support to develop a program within the department. Further, there was inadequate

understanding among the global research community of the special vulnerabilities of abalone populations to

overharvest (ADFG Report to Alaska Board of Fisheries 1999).

The decline of the abalone is probably a long-term condition now that sea otters have expanded to occupy

much of their former range. Otter populations have grown exponentially since their reintroduction into outer

coastal waters of southeast Alaska in the 1960s, and there are only a few pockets of abalone habitat that have

not yet seen a resurgence of otters. The two species share the same environment. Otters are uniquely

adapted to prey on abalone and it is clear that abalone cannot co-exist in commercial quantities with sea

otters (ADFG Report to Alaska Board of Fisheries 1999).

The decline of the abalone fishery, like the decline of the red sea urchin fishery, was not related to sea otter

predation. However, given current otter populations and population growth rates, it is virtually impossible

that these species will abound in commercial quantities in the future. By limiting the abalone’s population

from fully rebuilding - enough to support a commercial fishery - sea otters have diminished the future value

of Southeast Alaska’s commercial dive fisheries.

Observations of Sea Otter Predation on Commercial Species

ADFG field research and industry divers support the notion that sea otters are having a significant negative

impact on the harvest volumes of geoduck, urchins, crab and other marine species. Growing sea otter

populations have led to the depletion of many of these resources within the otters’ range, closing some

fisheries and leaving others economically unfeasible. In recent years, ADFG has closed 17 dive fishery harvest

areas due to sea otter predation.

Given the food source which developed during the last 100 years with little otter predation, it is expected the

outer coastline will eventually become continuously populated with sea otters from Dixon Entrance to well

north of Cape Spencer (Pritchett and Hoyt, 2008). In addition, many commercial fishermen have noted otter

populations in inside waters, expanding their range beyond the coastal areas.

This report contains estimates of financial losses incurred by commercial divers in the past and present, due to

sea otter predation. However, large sea otter populations inevitably threaten the future of dive fisheries and

crab fisheries; jeopardizing hundreds of jobs and tens of millions of dollars in economic activity for the region.


Map of Fishery Areas Negatively Affected by Sea Otters


Introduction

Purpose of the Research

The commercial harvest closures have resulted in measurable economic impacts on the seafood sector and on

communities in Southeast Alaska. Harvesters, processors, and seafood-dependent communities experience

lost employment, wages, tax revenue, and related economic activity. The Southeast Alaska Regional Dive

Fisheries Association (SARDFA) contracted with McDowell Group to quantify and explain these impacts in

2005. Since the 2005 report, otter populations have continued to grow, further impacting dive fisheries and

crab fisheries. This report uses current ADFG data and sea otter research to update the impacts of sea otter

predation on Southeast Alaska fisheries and communities.

Methodology

In 2005, the Alaska Department of Fish and Game (ADFG) estimated the lost guideline harvest level (GHL)

due to sea otter predation in the red sea urchin and sea cucumber fisheries. These estimates were contained

in a November 2005 memorandum. McDowell Group consulted with ADFG biologists who survey the fishery

and calculated the original estimates of lost GHL. Using new ADFG biological survey data regarding biomass

and sea otter predation, McDowell Group has employed the same methods as those used in 2005 to update

the estimates of economic loss.

The Alaska Department of Fish and Game provided McDowell Group with publicly available biomass survey

data and professional input (based on survey experiences and institutional knowledge). The scientific survey

data and interviews with expert professionals in the department are used in this report. In addition, prior to

release of this report, ADFG professionals reviewed the report to ensure data and information provided by

ADFG is objectively and accurately represented.

It is important to note, however, ADFG has not conducted controlled experiments to examine the effects of

sea otter predation on invertebrate populations. Their estimates are based on regular, direct observations

made during dive surveys and the department’s expertise as fishery managers.

Estimates of lost harvest volume were combined with average ex-vessel price data from ADFG to estimate the

lost value in ex-vessel earnings. Wholesale values are based on data from the ADFG Commercial Operators

Annual Report (COAR) database.

Wholesale value impacts are inclusive of impacts reflected by the loss of ex-vessel value. This is because

wholesale value of a product, or the revenues a processing company gains through sale of the product, must

pay for the expenses incurred in the procurement and processing of that product. This includes the purchase

of the raw material from harvesters, which is reflected as the ex-vessel value.


Sea Otters in Southeast Alaska

Species Profile and Diet

Sea otters (Enhdyra lutris) are a member of the weasel family and a significant predator in the ecosystems of

much of coastal Alaska, from Southeast to the Aleutian Islands. Their average life span is 15 to 20 years. Adult

male otters weigh typically weight 70 to 90 pounds and average about 4.5 feet in length, while females

average 40 to 60 pounds.

The sea otters’ only natural predators are sharks, killer whales (orcas), and bald eagles. Sharks and killer

whales are not particularly plentiful in Southeast Alaska, and there is no shortage of other food sources for

these predators. There is a very narrow window for bald eagles to hunt sea otter pups. Relatively soon after

being born, the pups are able to dive and evade the eagles.

Sea otters are the only marine mammal without blubber. As a result, the animals have a high metabolism and

require large amounts of food to survive. Sea otters in captivity will consume up to 25 percent of the body

weight per day.1

Instead of blubber, sea otters have a dense, water resistant coat which traps air close to their body insulating

them from the frigid waters of the North Pacific. Sea otters have the densest coat of any mammal, with

roughly a million hair follicles per square inch. By comparison, the human scalp has only 20,000 hairs in total.

One male otter, therefore, can consume up to 7,300 pounds of food in one year.

Sea otters typically forage in depths of 9 to 27 feet; however, a dive of 291 feet was recorded by an animal

which drowned while attempting to remove bait from a crab pot.

Many studies have been conducted on the foraging habits of sea otters. Aside from the tremendous volume

of food needed to sustain otters, researchers found significant differences in foraging habits depending on

location and available prey. Antonelis et al. (1981) and Ostfeld (1982) found evidence to confirm the

hypothesis that otters choose prey with the highest ratio of caloric-value to energy expended foraging

(Barnes 2002).

Other studies tend to support the notion

that sea otters are opportunistic

generalists which adapt their predation to

their environment. Studies from the

Aleutian chain to Prince William Sound to

Southeast Alaska have found different

foraging habits. The most recent study,

(Hoyt 2010), is collecting foraging data on

sea otters in southern Southeast Alaska.

Preliminary data from this study suggests

when sea otters move into new areas they

1 U.S. Fish and Wildlife Service. “Wildlife Biologue – Northern sea otter in Alaska (Enhydra lutris kenyoni).” p2.


are more likely to prey on commercials species. Over all, that study suggests commercial species make up 10

percent of the sea otter diet in southern Southeast Alaska.

Historical Population

Sea otters were completely removed from their natural range in Southeast Alaska by intense pressure from fur

traders in the 18th and 19th centuries. Prior to the fur trade period sea otter populations in the entire North

Pacific Rim – extending from Japan to Alaska to Baja California – ranged from 200,000 to 300,000 (Hoyt

2010). Sea otters were believed to have been eliminated from Southeast before 1900 (Pitcher 1989). In 1911,

an international treaty, the North Pacific Fur Seal Convention, passed protecting sea otter populations in the

United States, Russia, and Japan from further intensive exploitation.

The reintroduction of the sea otter into the Southeast region occurred from 1965 to 1969. A total of 402

animals were relocated from the Aleutian Islands and from Prince William Sound. Otter relocation sites

included Khaz Bay, Yakobi Island, Biorka Island, the Barrier Islands, the Maurelle Islands, and Cape Spencer.

The Southeast Alaska sea otter population remained low until 1987 when it began a period of rapid growth

(Pitcher and Imamura, 1990).

Since that time, sea otter populations have been increasing, and the range of the animals has expanded and

shifted correspondingly. The most recently completed population survey, conducted in 2002 and 2003,

estimated the Southeast sea otter population at 8,949 animals. Based on aerial surveys performed in 2010

southern Southeast Alaska sea otter populations are believed to be growing at 12 percent per year. Sea otter

populations in northern Southeast and Glacier Bay are believed to be growing at 4 percent (Hoyt 2011,

personal communication).

Estimated Southeast Alaska Sea Otter Population, 2002 - 2015

Season Last Population

Survey (2002/2003)



Coefficient of Variation

(CV%)

Southern Southeast

12% Annual Growth Rate 5,8451 14,472 22,772 0.14

Northern Southeast


Glacier Bay


Total Southeast Alaska 8,949 18,890 27,940 - 1Population estimate is from 2003. 2Population estimate is from 2002. Source: U.S. Fish and Wildlife Service, Hoyt 2011 (personal communication), and McDowell Group calculations.

Based on 2003 survey work, and a 12 percent annual growth rate, the current sea otter population of

southern Southeast is believed to contain about 14,500 animals. By 2015, the southern Southeast population

is expected to exceed 22,700 animals.


With a large food source available, high population growth rates will likely persist for some time. By 2015, the

Southeast Alaska sea otter population is conservatively projected to contain 27,940 sea otters. Given current

foraging research and a conservative estimate about body weight (50 lbs.) and daily food intake (20 percent

of body weight), a sea otter population of 27,940 would consume just over 10 million pounds of commercial

species per year in Southeast Alaska. The entire 2010 Southeast Alaska harvest in the dive fisheries and

Dungeness crab fisheries was 5.9 million pounds. Southeast Alaska sea otters consumed an estimated 6.9

million pounds of commercial species in 2011.

Population growth rates may actually increase if otters migrate further outside of their current territory. Sea

otter populations can grow by 20 percent per year when colonizing new areas with sufficient food sources

and few predators (Watson 2000). From 1975 to 1987, the growth rate of the sea otter population in

southeast Alaska was estimated at 17.6 percent per year (Estes 1990).

Population growth rates are limited primarily by three factors: abundance of food, predators, and population

size. As a population grows larger, it consumes more resources and mortality rates increase. The fact that sea

otter populations are growing three times faster in southern Southeast, despite a population which is three

times larger would indicate a substantial food source available to the southern Southeast otters. One of the

key differences between northern and southern Southeast, as they relate to sea otters, is the presence of large

macroinvertebrate populations in the southern region.

Updated sea otter population figures will be forthcoming. The U.S. Fish and Wildlife Service (USFWS)

performed aerial surveys during the summer of 2010 and 2011, but has not yet released their findings.

Recent Sea Otter Research in Southern Southeast Alaska

The most direct observation of sea otter effects on commercial fisheries comes from dive surveys performed

by ADFG biologists and an ongoing North Pacific Research Board project headed up by researchers from the

USFWS and the University of Alaska – Fairbanks (UAF).

ADFG performs annual dive surveys on areas open to commercial dive fisheries. Divers survey the near-shore

seabed in pairs for sea cucumbers, geoducks, and sea urchins covering 2-meter-wide transects. Sea otter

presence is noted during these surveys.

Observations made by ADFG divers on the outer coast of Southeast Alaska suggest sea otters select red sea

urchins and pinto abalone when foraging on rock habitat and on several species of clams including geoduck

clams when foraging on soft sand and mud substrate. Once these species have been depleted it appears they

turn to less desirable prey such as sea cucumbers and snails (Walker, Pritchett and Hoyt, 2006).

A collaboration of researchers and specialists from UAF and USFWS embarked on a four-year project

beginning in July 2010 to study interactions between sea otters and commercially important prey in southern

Southeast Alaska. The project will also survey sea otter populations and study movement, habitat, and diets of

otters in Southern Southeast Alaska. Preliminary results from this project have revealed the following:

• Otters can consume up to 23 percent of their body weight in a day, as they have a very high

metabolic rate.


• Distribution of sea otter populations have grown and moved further inland from outer coastal areas.

• Preliminary foraging data suggests commercially important species make up 10 percent of sea otters’

diet. (However, this data was collected from areas with relatively small populations of commercial

dive species, and other studies have noted different foraging behavior in different regions).

• When sea otters initially colonize an area, they consume larger amounts of commercially important

species such as sea cucumbers and Dungeness crab.

POTENTIAL CONSEQUENCES FOR SEA OTTERS AND COMMERCIAL FISHERIES

The sea otter population will likely continue to expand rapidly in coming years as otters consume the large

biomasses of crab and macro invertebrate, species which built up in the absence of sea otters during the past

century. When these biomasses have been depleted otters will need to find other food sources and many may

die off due to starvation. However, because sea otters are opportunistic generalists, it is likely commercial dive

fisheries and Dungeness crab fisheries in Southeast Alaska may never return to biomass levels that allow

sustainable commercial harvests.

The natural balance between sea otters and their prey, which existed before fur traders wiped out sea otters

in Southeast Alaska, did not allow for an imbalance between sea otters, crabs, and macro invertebrates. The

population of one group either limited or fueled growth in the other. In such a situation, large-scale

commercial dive fisheries and Dungeness crab fisheries may not be possible because crab and macro

invertebrate populations would not be able to reach a size large enough to support a fishery of current

proportions (given unabated sea otter predation).

In short, commercial dive fishing and large populations of sea otters cannot coexist in the same waters. In

addition, once the commercially viable biomass of crab and macro invertebrates – such as sea cucumbers and

geoducks - is gone, it likely will not return given sustained sea otter predation.


Southeast Alaska Dive Fisheries

Southeast Alaska dive fisheries occur primarily during the fall and harvest three species of bottom-dwelling

marine invertebrates: geoduck clams (Panopea generosa), California sea cucumbers (Parastichopus

californicus), and red sea urchins (Strongylocentrotus franciscanus). All three fisheries occur primarily in

southern Southeast Alaska waters. Entry into the fishery is limited, but those who hold permits compete to

harvest commercial species within the limits of guideline harvest levels established by ADFG.

Alaska dive fisheries started to develop in the mid-1960s, with a fishery for pinto abalone. In the 1980s

commercial dive fisheries developed for sea cucumbers, sea urchins, and geoducks. In 2000, the Alaska

Commercial Fisheries Entry Commission (CFEC) limited access to the fishery, restricting further growth in the

number of participants.

In 2010, Southeast Alaska dive fisheries produced a first wholesale value of $16.7 million and paid out $9.4

million to divers. Roughly 180 permitted divers participated in the fishery in 2010 for average earnings of

$52,100 per diver. This revenue is shared with crew, as the average commercial diver employs 0.8 crew

members according to surveys done by the Alaska Department of Labor and Workforce Development.

Impacts to the Southeast dive fisheries extend beyond payments made to divers. The fisheries occur during

the fall, after the busy summer season when harvests of salmon, halibut, black cod, and herring are finished

(or nearly finished). Dive fishery harvests provide processors with additional revenue and the ability to extend

some seasonal processing jobs by allowing some processing staff to handle dive fisheries production. In

addition, the fisheries add to the state, local, and federal tax base and create business for local dive shops,

transport companies, and other related businesses.

Geoduck Clams

Geoduck clams command the highest price of the three dive species. Virtually all Alaska geoducks are

exported to China and in 2010 geoduck clams sold for an average wholesale price of $8.72 per pound.

Quality geoducks, in the proper retail market, can command prices upwards of $20 per pound.

Southeast Alaska Geoduck Clam Dive Fishery Snapshot

2010/11 Season Pct. Change Since 2005/06

Number of Active Divers 69 -3%

Average Permit Value $81,600 +93%

Total Harvest (in lbs.) 887,500 +39%

Total Ex-Vessel Value $5.9 million +197%

Average Ex-Vessel Price $6.67 +114%

Total First Wholesale Value $8.0 million +186%

Average First Wholesale Price (per processed lb.)

$8.72 +94%

Average Revenue Generated Per Diver $115,900 +195%

Source: ADFG.


Geoduck fisheries take place throughout southern Southeast Alaska, and in waters surrounding Baranof

Island. A total of 69 divers fished in 2010, although there were 91 permits for the fishery. The fishery had an

ex-vessel value of $5.9 million in 2010, and a wholesale value of $8.0 million.

The value of the fishery has increased in recent years, as prices and harvest volumes have both risen. Harvest

volume has grown in spite of sea otter predation because new harvest areas were discovered and added to

the fishery. However the 2011/12 quota is only 557,900 pounds – the lowest since 2003 when there were

fewer harvest areas. Further harvest reductions are likely because most of the region has been surveyed and

areas with commercial quantities have already been opened. So as established areas lose GHL to otter

predation, new areas are not expected to make up for the shortfall as they have in the past.

During the past several years, SARDFA surveyors have found substantial geoduck clam beds but in some

instances did not attempt to open these areas because sea otters where active in the vicinity. By the time the

areas could be surveyed, studied, and opened (at a cost ultimately borne by the industry) the beds would

most likely be depleted below a commercially viable level.

Sea Cucumbers

Sea cucumbers are also sold primarily into Chinese markets. Sea cucumbers are raised in large numbers in

China in artificial ponds and man-made tide pools. Wild Alaska sea cucumbers tend to be much larger and

have higher nutritional value, therefore command a premium price in the Chinese market.

Southeast Alaska Sea Cucumber Dive Fishery Snapshot

2010/11 Season Pct. Change Since 2005/06

Number of Active Divers 180 -9%

Average Permit Value $11,300 +27%

Total Harvest (in lbs.) 1.27 million -12%

Total Ex-Vessel Value $3.4 million -

Average Ex-Vessel Price $2.65 +16%

Total First Wholesale Value (per processed lb.) $8.1 million +60%

Average First Wholesale Price $10.88 +45%

Average Revenue Generated Per Diver $45,000 +75%

Source: ADFG.

A total of 180 divers fished in 2010, although there were 291 permits for the fishery. Alaska sea cucumbers

had an ex-vessel value of $3.4 million in 2010, and a wholesale value of $8.1 million.

The fishery’s value has increased substantially in recent years due to rising prices. Because areas are only

harvested once every three years, the harvest can fluctuate greatly from year to year. Despite the fluctuations

due to harvest area rotation, the 2011/12 quota is very low. The 2011/12 quota of 999,000 pounds is the

lowest since the late 1990s.


Red Sea Urchins

Red Sea Urchins are harvested for their gonads, which is a delicacy in Japan. Male and female sea urchin

gonads, both known as uni in Japanese, are served in sashimi or in sushi.

Participation in the urchin fishery has declined since 2000, although 2010 posted the first increase in

participation since 2004. Still, only 12 divers fished in 2010, out of 71 permits. The fishery had an ex-vessel

value of $148,000 in 2010. The average gross earnings of $12,300 per diver in 2010 is the lowest since

access to the fishery was limited in 2000. An industry source reports only “one or two” divers are

participating in the 2011/2012 fishery, with only one buyer.


Economic Impacts of Sea Otter Predation

As sea otter populations have recovered in areas of the Pacific Coast, conflict has arisen with commercial and

subsistence fisheries. Sea otters prey on sea urchins, Dungeness crab, shrimp, clams, abalone, sea cucumbers,

and geoducks, among other animals. There are multiple studies that note sea otter population growth can

have a negative effect on commercial stocks of these species, potentially resulting in the closure or drastic

reduction of the commercial fishery. In one such example, Watson and Smith, in their 1996 paper examining

sea otter/fishery interactions in British Columbia, noted there is “no doubt that sea otters threaten urchin

fisheries.”

Indeed, as sea otters have reestablished themselves in various areas of Southeast Alaska, formerly abundant

stocks of several invertebrate species have been locally depleted below commercially harvestable levels. Since

1993 the Alaska Department of Fish and Game has closed 17 dive fishery harvest areas due to presumed sea

otter predation. The Department estimates sea otter predation affects 39 percent of Southeast dive fishery

harvest areas.

Summary of Dive Fishery Areas Affected by Sea Otter Predation

Species Total

Harvest Areas

Areas Closed Due to Sea Otters

Areas Closed, Presumably Because of Sea Otters

Areas Affected by Sea Otters

but Not Closed

Percentage of Areas Affected or Closed Due to Sea Otters

Geoducks 41 0 0 27 66%

Sea Cucumbers 67 3 4 12 28%

Red Sea Urchins 59 4 6 9 32%

Total 167 7 10 48 39%

Source: ADFG.

The financial impact of sea otter predation affects commercial divers, processors, dive shop owners, and

communities both inside and outside of Alaska. This section focuses on the cost of sea otter predation to

divers and processors, who have lost revenue in the form of ex-vessel earnings and wholesale revenues due to

sea otters.

Sea otter predation has had obvious and measureable economic impacts on the sea cucumber, red sea

urchin, geoduck, and Dungeness crab fisheries of Southeast Alaska. This report quantifies the estimated

impacts sea otters have had on these species. In addition, sea otters affect the tanner and king crab fisheries

of Southeast Alaska; however, data to quantify these impacts on these fisheries is not yet available.


Sea Cucumbers

Historical Harvest and Value

Sea cucumber fisheries occur throughout much of Southeast Alaska, in waters surrounding Prince of Wales

Island, including Clarence Strait, east to the Behm Canal and waters around Revillagigedo, Gravina, and

Annette Islands, and south. Fisheries also occur around Sitka, and in Sumner and Chatham Straits. Each

subdistrict opens once every three years. Although divers are allowed to harvest sea cucumbers from October

through March of the following year, virtually 100 percent of the harvest occurs during October and

November. So although the 2011/12 season will run through March 31, 2012, most of the GHL has already

been harvested.

Sea Cucumber Ex-Vessel Value and Participation 2001 - 2010

Source: CFEC.

In 2000, the Commercial Fisheries Entry Commission limited access to the fishery. Since limited access to the

fishery, participation has ranged from a peak of 234 permits fished in 2001 to a low of 168 permits fished in

2009. A total of 180 permits were fished in 2010, and fishermen earned a total of $3.2 million or $17,850 per

diver.

From 2007 to 2010, ex-vessel prices ranged from $2.86 to $2.56 per pound, but prices are much higher in

2011. Reports from the grounds indicate divers are being paid $5.50/lb. for sea cucumbers this season. While

the price appreciation is certainly a positive for fishermen, total ex-vessel values may not increase as much

because the guideline harvest level for the 2011/12 season is down. Fishermen will be allowed to harvest

roughly 1 million pounds of sea cucumber this season, a 12 percent decline from the 2008/09 season - the

last time these this group of subdistricts was harvested.

0

50

100

150

200

250

$0

$500,000

$1,000,000

$1,500,000

$2,000,000

$2,500,000

$3,000,000

$3,500,000

$4,000,000

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

Total Ex-Vessel Value Fishers Fishing Permits


Impacts of Sea Otters on Southeast Alaska Sea Cucumber Fishery

Sea otters are opportunistic generalists, consuming a wide variety of near-shore prey. Data collected in 2010

on the foraging habits of sea otters near Kake, Alaska revealed sea cucumbers made up 3.1 percent of the sea

otters’ diet. Similar foraging observations were made in Southwest Alaska during a 2003 study.

Although sea cucumbers do not represent the majority of sea otters diet, otters do consume large amounts of

sea cucumbers each year which has had an adverse of effect on the sea cucumber fishery.

Since 1996, sea otter predation has resulted in an estimated lost GHL of 3.25 million pounds worth $5.3

million in ex-vessel terms and $8.4 million in wholesale markets.

In 2011, sea otter predation led to a loss of roughly $7,000 for every active sea cucumber diver.

Estimated Sea Cucumber GHL and Value Lost Due to Sea Otters, 1996/97 – 2011/12

Season GHL Lost

Due to Sea Otters

Ex-Vessel Price ($)

Estimated Ex-Vessel Value Lost Due to Sea Otters

First Wholesale Value/lb. (round

weight basis)

Estimated Wholesale

Value Lost Due to Sea Otters

2011/12* 235,000 $5.50 $1,293,000 $9.50 $2,231,000

2010/11 151,000 $2.65 400,000 $6.37 961,000

2009/10 192,000 $2.59 497,000 $3.78 725,000

2008/09 241,000 $2.56 617,000 $3.94 949,000

2007/08 116,000 $2.86 332,000 $4.40 511,000

2006/07 143,000 $1.99 285,000 $3.35 480,000

2005/06 184,000 $2.29 421,000 $3.45 634,000

2004/05 140,000 $2.12 297,000 $3.48 488,000

2003/04 150,000 $1.47 213,000 $3.48 522,000

2002/03 84,000 $1.26 106,000 $2.51 211,000

2001/02 100,000 $1.75 175,000 $2.43 243,000

2000/01 130,000 $2.23 290,000 $2.41 313,000

1999/00 59,000 $1.94 115,000 $2.91 172,000

1998/99 40,000 $1.55 62,000 $3.09 124,000

1997/98 90,000 $1.66 147,000 $3.37 304,000

1996/97 34,000 $1.28 44,000 $2.44 83,000

Total 3,254,000 - $5,294,000 - $8,951,000

* 2011/12 data is preliminary and based on prices reported by industry. Source: ADFG data and McDowell Group estimates.

Sea otter predation has forced closures, been observed, or affected 19 sea cucumber harvest areas out of a

total of 67 harvest areas. Since 1993, ADF&G has closed three harvest areas specifically due to sea otter

predation and has noted four additional areas were probably closed due to sea otters. Two new harvest areas

were closed in 2011, specifically due to sea otters.


Geoducks


Currently there are 39 commercial geoduck clam harvest areas in Southeast Alaska and 2 control areas not

open for harvest. All of these areas are located in southern Southeast Alaska, with most of the GHL contained

in areas surrounding the communities of Ketchikan, Craig, and Sitka.

Since 2004, and particularly in the last three years, the Southeast Alaska geoduck fishery has become a

lucrative fishery. Ex-vessel prices for geoducks have nearly tripled since 2008. Reports indicate geoduck divers

are receiving $10.50/lb. from processors this season (2011/12).

Geoduck prices have increased in recent years primarily because coordination between government

regulators, fishery managers, and commercial divers has improved. Better communication and coordination

has allowed the industry to now sell all geoduck clams as live product. Live geoduck clams command a

significantly higher price.

Geoduck Ex-Vessel Value and Participation, 2002 - 2010

Source: CFEC.

Harvest volume has been relatively steady since 2004, ranging from 557,900 to 824,800 pounds.

Participation in the fishery has also been steady, with 55 to 71 divers participating in the fishery. In 2010, a

total of 69 divers out of 91 permit holders harvested geoducks.

0

10

20

30

40

50

60

70

80

$0

$1,000,000

$2,000,000

$3,000,000

$4,000,000

$5,000,000

$6,000,000

$7,000,000

2002 2003 2004 2005 2006 2007 2008 2009 2010

Total Ex-Vessel Value Fishers Fishing Permits


Impacts of Sea Otters on Southeast Alaska Geoduck Clam Fishery

Sea otter predation has become more evident in geoduck clam fisheries since the early 2000s (Walker 2011,

personal communication). With geoduck fisheries becoming more commercially important in recent years,

these adverse effects have become more costly for commercial divers.

Otter predation in the geoduck fishery is especially evident. Otters dig large holes into the seabed, pull up the

geoduck clam, eat the meat and discard the shells – leaving behind a large hole and shell debris which divers

note in their surveys. Surveys performed in 2009 on the Portillo Channel (Subdistrict 103-50) area revealed

notable otter presence in 70 of 74 transects. Surveys performed on the Lower Cordova Bay (102-10 and 103-

11) area showed sea otter presence in over half that district’s 60 transects (Rumble and Siddon, 2011).

McDowell Group employed the same methodology used by ADFG to estimate effects on the sea cucumber

and sea urchin fisheries from 1996/97 to 2005/06 to estimate geoduck harvest volume and value lost to sea

otter predation.

Evidence of sea otter predation has been observed at 27 of the 39 geoduck harvest areas. Biomass has

decreased significantly in seven of these 27 areas since 2003. Given the noted sea otter activity in these

geoduck fishery areas and lack of other natural predators, it is believed the declining biomass can be

attributed to sea otters for these seven harvest areas.

Since 2005, sea otter predation has resulted in an estimated lost GHL of 530,500 pounds worth $3.2 million

in ex-vessel terms and $4.2 million in wholesale markets. In 2011, sea otter predation was particularly costly,

leading to a loss of roughly $20,000 for every active geoduck diver. This is money which is directly taken out

of family budgets and local economies.

Estimated Geoduck GHL and Value Lost Due to Sea Otters 2005/06 – 2011/12

Season GHL Lost

Due to Sea Otters

Ex-Vessel Price ($)

Estimated Ex-Vessel Value Lost Due to Sea Otters

First Wholesale Value/lb. (round

weight basis)

Estimated Wholesale

Value Lost Due to Sea Otters

2011/12* 140,900 $10.50 $1,479,000 $13.97 $1,969,000

2010/11 43,800 $6.61 289,000 $9.03 77,000

2009/10 142,300 $5.48 780,000 $6.46 919,000

2008/09 18,700 $3.66 69,000 $5.38 101,000

2007/08 95,100 $3.50 333,000 $4.76 452,000

2006/07 10,200 $3.67 37,000 $5.00 51,000

2005/06 79,500 $3.15 251,000 $4.06 323,000

Total 530,500 - $3,237,000 - $4,210,000

* 2011/12 ADF&G data is preliminary and values are based on prices reported by industry. Source: ADFG data and McDowell Group estimates.

Geoducks are in a precarious situation due to sea otters. While prices are high and divers are earning good

money harvesting them, that could soon end.


Evidence of sea otter predation has been observed at 27 geoduck fishery areas, but only seven of those areas

exhibited significant biomass declines in recent years. However, if those other areas with sea otter activity

become harder hit, the impact on the fishery could be devastating because sea otter predation has been

noted in harvest areas containing 70 percent of the geoduck biomass. Should otters focus on geoducks as a

food source more in the future, it is unlikely the geoduck biomass could reproduce quickly enough to support

a commercial fishery which is economically feasible or biologically sustainable.

Red Sea Urchins


Participation in the Southeast Alaska red sea urchin fishery has declined rapidly in recent years, approaching

zero. During the 2011/12 season, only “one or two” are harvesting urchins with only one buyer, according to

an industry source. In 2005, the fishery harvested 1.6 million pounds of red sea urchin worth an ex-vessel

value of $453,000. By 2010, production dwindled to 509,000 pounds, harvested by 12 divers who shared

$147,700 in total ex-vessel value. The 2010 harvest was just 10 percent of the 4.95 million pound guideline

harvest level.

Red Sea Urchin Ex-Vessel Value and Participation, 2001 - 2010

Source: CFEC.

In the red sea urchin fishery, dwindling participation is not being driven by sea otter predation, but rather a

falling market value for the product. The gonads of red sea urchins, called uni by the Japanese, are a popular

sushi item. Virtually all of Alaska’s urchin production gets exported to Japan. In general, other urchin fisheries

in Russia and the west coast harvest enough supply for the Japanese uni market. In addition, there have been

market issues with Alaska urchins stemming from inconsistent quality (due to biological factors) and

mishandled product by shippers.

0

5

10

15

20

25

30

35

40

45

0

200,000

400,000

600,000

800,000

1,000,000

1,200,000

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

Total Ex-Vessel Value Divers Fishing Permits


In 2000, red sea urchins were fetching $0.45/lb. on the grounds. Ex-vessel prices have steadily declined since

then, and in 2010, the 12 divers who participated in the fishery were paid an average price of $0.29/lb.

Meanwhile, ex-vessel prices for geoducks and sea cucumbers have risen substantially during this period,

along with fuel costs and other operating costs. Low volume and the opportunity cost of harvesting urchins,

when a diver could be targeting geoducks or sea cucumbers, has made the fishery uneconomical for most

divers and processors.

Impact of Sea Otters on the Southeast Alaska Red Sea Urchin Fishery

In 2008, the average sea urchin diver grossed $24,000, and prior to that time divers generally averaged

$20,000 to $30,000 per season. Because sea urchins are a major food source for otters, the financial impact

on commercial divers was significant.

Sea otter predation resulted in an estimated harvest shortfall of 3.1 million pounds from 1996 to 2005 worth

1.0 million in ex-vessel terms and 4.0 million in wholesale value.

Estimated Red Sea Urchin GHL, Harvest and Value Lost Due to Sea Otters, 1995/96 – 2005/06

GHL Lost Due to Sea Otters

Estimated Harvest Lost Due to Sea

Otters (adjusted lbs.)

Estimated Ex-Vessel Value Lost

Due to Sea Otters

Estimated Wholesale Value Lost Due to

Sea Otters

Total 6,285,000 3,102,000 $1,024,000 $3,972,000

Source: ADFG data and McDowell Group estimates.

Participation in the fishery is now so low that many figures on the fishery are confidential, and since only a

small portion of the GHL is harvested, the impact of sea otters in recent years is likely very small. For these

reasons, sea otter impacts have not been calculated for the 2006/07 through 2011/12 seasons. However, sea

otters did have a large impact on the fishery in the past, and will continue to feed on urchins in the future. In

an area from the southern shoreline of Sitka Sound to West Crawfish Inlet it was estimated 16 million sea

urchins were consumed by sea otters over a 15-month period from December 1992 through February 1993

(Davidson, et al., 2008).

Although the majority of the red sea urchin fishery will go unharvested this season, sea otters are still having a

large impact on the biomass. The 2011/12 GHL is 3.3 million pounds; a 42 percent decline from the 2006/07

season (which marks two fishery area rotations). If this trend continues, the fishery may not improve

regardless of market price.


Dungeness Crab

Dungeness crab are a substantial food source for otters. Dungeness crab are typically found at depths of 15

to 100 feet, are plentiful in many Southeast Alaska estuaries, and offer a good nutritional return per unit of

energy expended.

It is clear areas with a significant sea otter presence have fared much worse in recent years than areas which

are not near large sea otter populations. Out of 15 shellfish districts in Southeast Alaska, six have significant

sea otter populations or include translocation sites (where sea otters were released in the 1960s).

These six districts have lost nearly 1 million pounds of harvest activity while districts without sea otters have

seen harvests increase slightly since the early 2000s. The greatest loss comes from District 9, near Kake, which

had a harvest decline of 776,000 pounds from 2007 to 2010 alone.

Southeast Alaska Dungeness Crab Harvest

Note: Districts with major sea otter presence include districts: 3, 5, 6, 9, 10, and 13. Source: ADF&G harvest data.

It is very likely sea otter predation is the driving force behind the majority of these lost harvest volumes.

Fishermen and biologists note the effect of sea otter predation. Not surprisingly, fishermen are leaving the

fishery. The Wrangell-Petersburg census area, which includes Kake and the surrounding waters, was home to

fishermen who landed crab under 134 Dungeness crab permits in 2005. By 2010, only 111 permits were

fished – a loss of 23 permits or roughly 46 jobs (including 1 crew member and the skipper).

0

500,000

1,000,000

1,500,000

2,000,000

2,500,000

3,000,000

Avg. Harvest 2000-2002 Avg. Harvest 2008-2010

Har

vest

Vo

lum

e (l

bs.

)

Districts with Major Sea Otter Presence Districts with Little Sea Otter Presence


According to the Alaska Department of Labor and Workforce Development, the Southeast Alaska crab

fisheries employed 638 workers in 2009. The majority of these jobs are in the Dungeness crab fishery.

Expanding sea otter populations seriously jeopardize these jobs.

METHODOLOGY FOR ESTIMATING DUNGENESS CRAB HARVEST LOST TO SEA OTTER PREDATION

Using field research done by ADFG, USFWS, and UAF, several Dungeness crab harvest districts were identified,

which included waters known to have significant populations of sea otters. Crab harvests from these areas

were compared to harvests in other districts. In effect, districts with fewer sea otters were treated as a control

group. If sea otter predation was a serious issue in the areas identified, the harvest of crab should decrease in

those districts relative to harvests in other districts (with fewer otters). This is exactly what took place from

2000 to 2010.

Impact of Sea Otter Predation

Districts 3, 5, 6, 9, 10, and 13 – located in southern part of the region and the outside coast line, have lost

out on an estimated 2.7 million pounds of Dungeness crab since 2000. It is assumed all or most of this loss is

associated with sea otters, as there are no other known factors which affect crab biomass in these districts

and not others in Southeast Alaska.

In 2000, these six districts with large sea otter populations, accounted for 61 percent of the Southeast Alaska

Dungeness crab harvest. By 2010, they accounted for just 33 percent; after seeing a gradual decline

throughout the decade relative to districts without large sea otter populations.

Since 2000, the lost harvest volume attributed to sea otters was worth $5.3 million in wholesale value and

$3.3 million in ex-vessel value.

Estimated Dungeness Crab Harvest and Value Lost Due to Sea Otters in Southeast Alaska, 2000/01 – 2010/11

Estimated Harvest

Lost Due to Sea Otters (live wt.)

Estimated Ex-Vessel Value Lost

Due to Sea Otters

Estimated Wholesale Value Lost Due to

Sea Otters

Total 2,681,000 $3,317,000 $5,301,000

Source: ADFG harvest data and McDowell Group estimates.


Quantifying the Impact of Sea Otter Predation

Dive fisheries in Southeast Alaska are managed by the Alaska Department of Fish and Game. Management is

supported by a tax on the ex-vessel value of red sea urchins, sea cucumbers, and geoducks. This tax is used

to pay for management staff and perform scientific dive surveys that allow managers to monitor the biomass

of commercial species in established subdistricts, or new harvest areas.

Dive surveys are performed by SCUBA divers surveying established, or new, subdistricts along 2-meter wide

transects running perpendicular to the shoreline. To complete transects, divers swim along the transect

holding a 2-meter rod made of white PVC pipe in a horizontal position. Transect direction is maintained by a

compass mounted on the rod.

Every harvest area gets surveyed before a fishery is opened for a given season, in addition to a group of

control areas which are surveyed every year. The

harvest areas, or subdistricts, open on a rotational

basis, depending on the species and results of the

dive surveys.

Dive surveys are expensive, but necessary for

sustainable fishery management. In addition to

providing data on the biomass, size, and density of

commercial species, the dive surveys also allow

managers a chance to maintain data on the

invertebrates’ habitat and eco-system. Divers have

noted the presence and evidence of sea otter

predation on each transect for each species, in

each fishery area. Areas affected by sea otters are

often distinguished by large holes with clam shell fragments (from where an otter has dug up a geoduck) or

sea urchin carcasses littering the seabed. In the case of sea cucumbers, no physical evidence is left because

otters consume the entire animal. However, divers note areas with active sea otter predation and have

attributed large biomass declines in various subdistricts to sea otters.

Detailed survey data from thousands of dives recorded by fishery biologists, combined with information on

historical biomass and GHL’s, allows for a conservative estimate of sea otter predation. The estimated harvest

volume lost due to sea otter predation can be translated into dollar terms by applying the ex-vessel price or

wholesale price of a particular species in a given year.

Because virtually 100 percent of the GHL is harvested in the geoduck and sea cucumber fisheries, only the

lost GHL is calculated and financial impacts are based on GHL. In the red sea urchin fishery, harvests volumes

have not historically met the GHL. Therefore, impacts on the red sea urchin fishery were adjusted to reflect

dollars and pounds lost are based the assumed harvest, and not on the GHL.

Photo Credit: Alaska Department of Fish and Game.


Accurately quantifying the impact of sea otter predation is only possible because ADFG data on sea otter

predation, affected areas, commercial harvests, biomass, and market values is very good.

Because of ADFG’s rigorous data collection, these estimates are believed to accurately portray the real, direct

impact of sea otters on commercial species. Without such data, other studies such as Loomis (2006) have

attempted to explain the value of sea otters in terms of existence value or the value of the public’s

“willingness to pay.” These estimates are theoretical and obtained by surveying a sample of the population

about what dollar value they place on knowing a certain species, in a certain locale, is flourishing or what

dollar value they would pay to engage in a suggested recreational activity involving the species. In contrast,

the effect of sea otter predation on commercial divers, seafood processors, and Southeast Alaska communities

is not hypothetical.


Sea Otter Predation Impacts on Communities

Sea otter predation has led to an estimated loss of $22.4 million in wholesale value for southern Southeast

Alaska communities since 1995. Lost sales for fishermen and processors are estimated to have resulted in

indirect and induced losses of $5.8 million during that time. These losses reflect lost economic activity in

industries outside the seafood industry in southern Southeast Alaska, resulting from lower wages, less

household spending by affected families, less spending on indirect business costs, and less taxes collected

from fisheries.

In total, sea otter predation is estimated to have cost southern Southeast Alaska communities $28.3 million

since 1995. Any revenue derived from eco-tours, expanded subsistence harvests (above what would normally

occur), or economic activity associated with scientific studies, stemming from sea otter expansion have likely

been negligible, in comparison.

Southern Southeast Alaska Communities Most Affected by Sea Otter Predation

Ketchikan Sitka Kake

Petersburg Craig Port Alexander

Klawock Hydaburg Wrangell

The livelihood of Southeast Alaska commercial divers, crab fishermen, tender operators, and seafood

processing workers is currently being jeopardized by expanding sea otter populations. These include

hundreds of basic sector jobs which form the foundation of a regional economy.

Residents of the Wrangell-Petersburg census area have seen 23 fewer permits fished in recent years, part of

which may be attributed to sea otter predation. Employment has not declined substantially in the sea

cucumber and geoduck fisheries, but sea otter predation is estimated to have cost each geoduck diver

$20,000 and each sea cucumber divers $7,000 in 2010. Based on the estimated value of product lost in

recent years and the amount of economic activity resulting from the typical full-time job in southern

Southeast Alaska, the secondary impacts of sea otter predation has been equivalent to a loss of 5 to 10 full-

time average-paying jobs (depending on the year).

The wholesale value of Southeast Alaska sea cucumbers, geoducks, red sea urchins, and Dungeness crab was

roughly $25 million in 2010. These fisheries employ roughly 625 fishermen and dozens more tender

operators and processing workers. Using economic multipliers developed by IMPLAN2, it is estimated the $25

million in wholesale value associated with these fisheries results in indirect and induced activity worth $6.5

million - equivalent to 53 additional full-time average-paying jobs3

2 IMPLAN is an economic modeling software package widely used to perform economic impact analysis.

. Just like commercial divers and crab

fishermen, these jobs are at risk of being lost as well. Indirect losses are more often more difficult to see, but

they are economically real, as less money circulates in the economy leading to contracting employment.

3 The estimated number of jobs created is calculated by dividing the value of the secondary impact ($6.5 million) by the average output created per full-time equivalent (FTE) job in Southeast Alaska ($123,992 per FTE job). Therefore, the term “average-paying” refers to a full-time job producing an average amount of economic output, and paid accordingly.


Literature Referenced

Alaska. Department of Fish and Game, Division of Commercial Fisheries. Preliminary Report to the Alaska

Board of Fisheries: Collapsed or Recovering Shellfish Fisheries in the State of Alaska

Barnes, Jennifer. 2002. Sea Otter Foraging and Feeding Behaviors: A Review. Prepared for the U.S. Marine

Mammal Commission. 27 pp.

. Regional

Information Report 1J02-06. October 1999.

Davidson, B., E. Coonradt, S. Walker, B. Meredith, J. Breese, D. Harris, T. Thynes, S. Forbes, M. Pritchett, Z.

Hoyt. Annual Management Reports of the 2004/2005, the 2005/2006, and the 2006/2007 Southeast

Alaska Commercial Fisheries for Geoduck Clams, Red Sea Cucumbers, and Red Sea Urchins. Alaska

Department of Fish and Game. May 2008.

Doherty, Phil. Executive director of SARDFA and former ADFG biologist. Personal communication. November

23, 2011.

Hoyt, Z., V. Gill, G. Eckert, S. Rice. “Recolonization, prey selection and resource competition by sea otters,

Enhydra lutris, in southern southeast Alaska.” November 2010 presentation.

Loomis, John. 2006. Estimating Recreation and Existence Values of Sea Otter Expansion in California Using

Benefit Transfer. Coastal Management, 34: 4, 387-404, First published on: 01 December 2006.

Pitcher, K.W. 1989. Studies of Southeastern Alaska sea otter populations: distribution, abundance, structure,

range expansion, and potential conflicts with shellfisheries. USFWS Cooperative Agreement No. 14-

16-0009-954. Alaska Department of Fish and Game, Anchorage. 65pp.

Pitcher, K. W. and K.K. Imamura 1990. Impacts of sea otter predation on Dungeness crab abundance in Cross

Sound-Icy Strait Area, southeastern Alaska. U.S. Fish and Wildlife Service Cooperative Agreement No.

14-16-009-954 Final Report:1-18.

Pritchett, M. and Z. Hoyt. Report to the Board of Fisheries, Miscellaneous Dive Fisheries. Alaska Department of

Fish and Game Fishery Management Report No. 08-63. December 2008.

Paul, Thomas W. 2009. Game transplants in Alaska. Alaska Department of Fish and Game, Technical Bulletin

#4, p108.

Rumble, J. and C. Siddon. Southeast Alaska 2009 Geoduck Stock Assessment. Alaska Department of Fish and

Game. October 2011.

Walker, S., M. Pritchett and Z. Hoyt. 2006. Report to the Board of Fisheries, Miscellaneous Dive Fisheries.

Alaska Department of Fish and Game Fishery Management Report No. 06-01:4.


Watson, J.C. and T.G Smith. 1996. The effect of sea otters on shellfisheries in British Columbia: In:

Invertebrate Working Papers. Reviewed by the Pacific Assessment Review Committee (PSARC) in 1993

and 1994. Ed. by C.M. Hand and B.J. Waddell. Can. Tech. Rep. Fish. Aquat. Sci. No. 2089 pp2 262-

303.

Watson, J. 2000. The effects of sea otters (Enhydra lutris) on abalone (Haliotis spp.) populations. In Workshop

on Rebuilding Abalone Stocks in British Columbia. Edited by A. Campbell. Can. Spec. Publ. Fish.

Aquat. Sci. 130. pp123-132.


Appendix 1: Map of Otters in Southeast Alaska

Source: Hoyt, Z., Gill, V., Eckert, G., Rice, S., “Recolonization, prey selection and resource competition by sea otters, Enhydra lutris, in southern southeast Alaska.” November 2010 presentation.

2010: 13% increase in distribution since 2003

5,845 Sea Otters in 2003 Survey


Appendix 2: Impact of Sea Otters on Dive Fishery Areas

Sea Cucumbers

FISHERY AREAS NEGATIVELY AFFECTED BY SEA OTTER PREDATION

Fishery Area Subdistrict(s)

Cape Chacon 102-10

Cordova Bay 103-11, 15

Long Island – Cordova Bay 103-21, 30

Hetta and Nutkwa 103-23, 25

Eastern Shore of Dall Island and Soda Bay 103-40-001, 002, 004

Bucarelli Bay 103-50

St Nicholas Channel 103-60, 70-002

Boca and Tonowek 103-80

West Dall Island 104-10, 20, 30

Port Camdon 109-43, 105-32

Deep Inlet and Sitka Sound South 113-38, 41

Sitka Sound North 113-40, 42, 43

AREAS CLOSED DUE TO SEA OTTER PREDATION


Sea Otter Sound 103-90

Affleck Canal and Port Beauclerc 105-10, 20

Shaken Bay 105-41, 42

Saginaw and Security Bay 109-44, 45

Tebenkof Bay 109-62

Baranof Island 113-31, 32, 33

Khaz Bay 113-71, 72, 73


Geoduck Clams



Kaigani Strait 103-30-001

Tlevak Strait 103-40, 50-009

South Cordova Bay 103-11

Bucareli Bay 103-50-003

Cone Island North 103-50-005, 104-40-005

Cone Island South and Paloma Pass 103-50-006, 104-35-006

Port Rea Marina 103-50-007

Portillo Channel 103-50-008

Port Mayoral (Control Area) 103-50-CON

East San Fernando Island 103-60-001

Maurelle Islands 103-70, 80, 104-40, 50-009

Ulitka Bay 103-70-001

Little Steamboat Bay 103-70-002

Steamboat Bay 103-70-003

Blanquizal Island 103-70-005

Palisades Islands 103-70-006

St. Nicholas Channel and North Lulu Island 103-70-007

Port Alice and Cone Bay 103-90-002

Turn Point 103-90-003

Davidson Inlet 103-90-004

Warren Island and Kosciusko Island 103-90-005, 105-41, 43, 50-005

Northwest Dall Island 104-20, 30-003

Port Santa Cruz 104-30-002

Taigud and Kolosh Islands 113-31, 41-004

Symonds Bay 113-31-002

Biorka and Legma Islands 113-31-003

Elovoi, Golf, and Gornoi Islands 113-31-005


Red Sea Urchins



Lower Clarence Strait 102-20

Tlevak Strait 103-40

Central Dall Island 104-20-001

AREAS CLOSED DUE TO SEA OTTER PREDATION


Cape Chacon 102-10

Dixon Entrance and Kaigani Strait 103-30

Bucareli Bay and Port Real Marina 103-50

St. Nicholas Channel 103-70

Southwest Dall Island 104-10

Meares Passage and Bucareli Bay 104-30

Western Baker Island and Cone Island 104-35

Western Noyes Island and Cone Island 104-40

Whale Bay 113-22

Baranof Island 113-11, 21

Documents

MCDOWELL GROUP 2011 Sea Otter Impacts Report